Method of, and an apparatus for, rinsing materialographic samples

ABSTRACT

The present invention relates to a method of, and an apparatus for rinsing materialographic samples. The apparatus includes a sample holder configured to receive materialographic samples, a rotation head configured to rotate the sample holder and a vessel configured to receive the sample holder and a rinsing liquid. The apparatus also includes means for filling and emptying the vessel with rinsing liquid, means for applying ultrasound to the rinsing liquid and a control means. The control means is configured to control at least one of filling of the vessel with a rinsing liquid by injecting rinsing liquid through an inlet provided in the vessel to submerge the materialographic samples in the rinsing liquid, subjecting the rinsing liquid and the materialographic samples to ultrasound, or rotating the sample holder including the materialographic samples relative to the vessel.

RELATED APPLICATIONS

This Application is a Divisional Application of U.S. patent applicationSer. No. 15/305,797 filed on Oct. 21, 2016, which claims priority to andis a National Stage Application of PCT/EP2015/058750 filed on Apr. 23,2015, which claims priority to Danish Patent Application PA 201470240filed on Apr. 24, 2014, the contents of which are all herebyincorporated by reference herein in their entireties.

The present invention relates, according to a first aspect, to a methodof rinsing/cleaning materialographic specimens such as cylindricalmaterialographic samples. In particular, the first aspect relates to amethod of cleaning metallographic samples.

According to a second aspect, the present invention relates to a rinsingapparatus configured for rinsing materialographic samples.

BACKGROUND OF THE INVENTION

In connection with obtaining materialographic samples, pieces of amaterial, e.g. a metal, are cut by abrasive cut off wheels in, forexample, materialographic cutting machines, such as metallographiccutting machines.

After a sample has been cut by a cut off wheel, the sample needs to beprepared for examination by one or more of grinding, lapping andpolishing a surface of the sample often in a stepwise finer manner.

Grinding may be defined as the rapid and often initial removal ofmaterial from a specimen either to reduce the specimen to a suitablesize or to remove large irregularities from the surface.

Lapping may be defined as the removal of material to produce a smooth,flat, unpolished surface. Lapping processes are used to producedimensionally accurate specimens to high tolerances.

Polishing may be defined as is the removal of material to produce ascratch-free, specular surface. Polishing is typically done at very lowspeeds using either polishing cloths, abrasive films, or speciallydesigned lapping plates.

Prior to preparation for examination, the samples are placed in, ormolded in, a base for easy handling. The base may constitute a sampleholder.

For the purpose of obtaining and examining e.g. metallographic samples,which typically are cylindrical, test objects are, as mentioned above,prepared by one or more of grinding, lapping and subsequently polishing.In between each step, the metallographic sample needs to be rinsed toremove coarse-grained debris and abrasives before the next and finerstep to avoid contaminating the following preparation procedure.

The normal procedure for rinsing such metallographic samples typicallyinvolves manually transferring the metallographic sample to a sink,washing the metallographic sample in a special soap, then inalcohol/methylated spirit, and manually drying the metallographicsample, either using a cloth, blow drying, or both. This procedure isdescribed in e.g. the ASTM standard; Geels, Kay: “Metallographic andMaterialographic Specimen Preparation, Light Microscopy, Image Analysisand Hardness Testing”; Lancaster, Pa., US, June 2007, section 5.1.2(pages 82-83).

It is a problem of the prior art that these actions are hard to performwithout getting smeared, and there is a risk of contaminating thesample. Further, it is difficult or not possible to obtain a constantquality of rinsing, whereby, replicability in the sampling procedure isdiminished. Yet further, the handling of special soap or alcohol is atrisk of inducing health and environmental problems. Yet further, it ishard to control the use of water, soap and alcohol in the manualprocess, often causing excess use, which increases the cost and wasteproduct, the latter, especially, being a potential environmentalproblem.

Also known in the art is a machine where a number of metallographicsamples are placed in a holder and where the samples are stepwiseground/polished. In between each step, an arm transports the holder withthe metallographic sample from the grinding site to a chamber filledwith soap water, submerging the holder into the soap solution, andsubjecting the holder with the metallographic samples to ultrasonicwaves. Subsequently, the arm extracts and transports the metallographicsample from the soap solution chamber and into a separate chamber,wherein clean water under pressure is sprayed on the soap-water soakedholder with the samples to rinse of the soap and any debris on theholder and metallographic samples.

Finally, in the same chamber, the holder and the metallographic samplesare dried by pressurized air. Such a machine is provided by theapplicant under the name Hexamatic and MAPS.

It is a problem, with the prior art device that it uses largerquantities of detergents/chemicals, and relatively large quantities ofenergy for drying.

Further, despite being a fully automated device, the process is slow ifthe rinsing quality is to be kept sufficiently high. Under section 5.1.2the ASTM standard; Geels, Kay: “Metallographic and MaterialographicSpecimen Preparation, Light Microscopy, Image Analysis and HardnessTesting”; Lancaster, Pa., US, June 2007, also mentions the use ofultrasound to clean specimens, where the specimens are placed in a tankfilled with water with a detergent, alcohol or organic solvent. In caseswhere the samples are particularly dirty, Geels suggest to use weakacids or basic solutions.

U.S. Pat. No. 5,985,811 A discloses a method of spray cleaningsemiconductors by rotating the material to be cleaned in a cleaningvessel while applying ultrasound to a flow of cleaning liquid being fedto the spraying nozzle. Ultrasound is applied to the cleaning liquidwith the purpose of generating free radicals in order to facilitatecleaning the semiconductors.

U.S. Pat. No. 7,317,964 B1 discloses a method of 3D high precisionreconstruction of microstructure specimens.

CN 103447937 A discloses an automatic grinding and polishing machine.According to the reference, after polishing of the samples is completed,the samples are moved into an ultrasonic washing box to carry outwashing of the samples.

U.S. Pat. No. 6,247,198 B discloses an apparatus for cleaning a wafer.The wafer is cleaned by brushes and placed in a cleaning liquid.Furthermore, ultrasonic vibrations are applied to the cleaning liquid byan ultrasonic generator.

US 2004/163682 A discloses a method for cleaning a semiconductor. Themethod initiates with generating acoustic energy oriented in asubstantially perpendicular direction to a surface of a semiconductorsubstrate. Then, acoustic energy oriented in a substantially paralleldirection to the surface of the semiconductor substrate is generated.

SUMMARY OF THE INVENTION

On this background, it is an object of the present invention to providea more efficient, reliable and consistent method of, and apparatus for;rinsing materialographic samples, which at the same time uses fewerresources such as detergents and other chemicals. Such materialographicsamples are samples, which are cut from a specimen and prepared bygrinding and subsequently polishing the sample in a number of steps,using stepwise finer grinding and polishing. The grinding and polishingof such samples is performed using ever finer grain size in the range of250 μm to 0.1 μm. For polishing, normally 0.1-35 μm grain size is usedand for grinding 10-250 μm grain size. Materialographic samples may bemost types of solid materials (polymer, ceramic, composite, electronic,etc.). In particular it is an object to provide a method of rinsingmetallographic samples.

This object is achieved by a method of rinsing materialographic samples(1) including, in an arbitrary or sequential order, the steps of:

-   -   arranging one or more materialographic samples to be rinsed in a        sample holder,    -   coupling the sample holder to a rotation head of a rinsing        apparatus,    -   placing the sample holder coupled to the rotation head in a        vessel (20) of the rinsing apparatus,

followed by, in a sequential order or not, the steps of:

-   -   commencing filling the vessel with a rinsing liquid by injecting        rinsing liquid through an inlet (26) provided in the bottom of        the vessel (20) thereby submerging the samples into the rinsing        liquid;    -   subjecting the rinsing liquid and the materialographic samples        to ultrasound, and    -   rotating the sample holder incl. materialographic samples        relative to the vessel.

wherein the step of subjecting the rinsing liquid and thematerialographic samples (1) to ultrasound is maintained at least duringfilling of the vessel (20) with rinsing liquid

The application of ultrasound prior to commencing rotation of the sampleholder allows for rinsing of the samples by means of ultrasound viasubstantially stagnant rinsing liquid. By this, increased rinsingefficiency is provided. Furthermore, as the rinsing efficiency isincreased, omission of rinsing agents is rendered possible. Finally, bythis, the rinsing process may take place in tap water.

By rotating the sample holder while applying ultrasound, it furthermorehas surprisingly been found that the rinsing of materialographic samplescan be shortened time-wise, while a more stable rinsing result isobtained. Further, the method according to the invention allows therinsing to occur quickly and with a greatly reduced or even eliminatedconsumption of detergents. It has been found that even pure water, ortap water, may be used as rinsing liquid. In the context of the presentapplication, by pure water is meant tap water without any additives,such as detergents, alcohol, or organic solvents, e.g. acetone, or weakacids or basic solutions.

In the prior art ultra clean water, desalinated water, or demineralizedwater is used in combination with detergents, alcohol, or organicsolvents. With the invention according to the present method this is notnecessary.

Further, the method allows a precise dosing of liquid/water, and reducedor eliminated use of drying with compressed air.

In an embodiment, the step of subjecting the materialographic samples inthe sample holder to ultrasonic waves is initiated during the filling ofthe vessel with rinsing liquid. Thereby it is achieved the eventualresidues/dirt from previous uses are loosened early in the rinsingprocess.

In a further embodiment the rotation of the sample holder is initiatedafter the ultrasound is initiated.

In yet another embodiment where said rinsing device comprises a lid forcovering said vessel, where said method comprises the step of injectingsaid rinsing liquid through a bottom of said vessel, where the path ofsaid injected rinsing liquid is deflected from a direction parallel tothe axis of rotation of the sample holder, and where said injection ofrinsing fluid is initiated before a step of closing set said lid iscompleted.

In yet another embodiment, the method further comprises the step ofemptying the rinsing liquid from the vessel while rotating the sampleholder in the vessel. In an embodiment hereof the application ofultrasound is maintained during the emptying of the vessel.

In yet another embodiment hereof, the rotational speed of the sampleholder is increased upon initiating the emptying of the vessel.

In yet another embodiment hereof, the method further comprises the stepof spraying alcohol or methylated spirit on the materialographic samples(1) in the sample holder after emptying the rinsing liquid from thevessel while rotating the sample holder in the vessel.

In yet another embodiment hereof, the vessel is evacuated by applying avacuum to an outlet of the vessel.

In all of the above mentioned embodiments the rinsing liquid may be purewater.

Further objects, features, advantages and properties of the method forrinsing materialographic samples according to the invention will becomeapparent from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present description, theinvention will be explained in more detail with reference to theexemplary embodiments shown in the drawings, in which:

FIG. 1, in a perspective view, shows details of a sample holder withsamples for a rinsing device for use in the method according to thepresent invention;

FIG. 2, in a side sectional view, shows details of a rinsing device foruse in the method according to the present invention;

FIG. 3, in a partly sectional side view, shows details of a liquidsupply and evacuation system according to one embodiment of theinvention;

FIG. 4, is a side view of the liquid supply and evacuation system shownin FIG. 3;

FIG. 5, in a perspective view, shows a rinsing apparatus for use in themethod according to the present invention;

FIG. 6, in a perspective view, shows details of an alternative sampleholder with samples for a rinsing device for use in the method accordingto the present invention; and

FIG. 7, in a perspective view, shows a retainer plate arranged on anupper face of a sample holder.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, the method of rinsingmaterialographic samples and a rinsing device 100 according to theinvention will be described by preferred embodiments.

In the figures, FIG. 5 shows a rinsing apparatus 100 for performing themethod according to the invention. The rinsing apparatus 100 comprises ahousing 101. A vessel 20 is arranged in the housing. An arm 102extending from the housing holds a lid 120, adapted for covering thevessel 20, see further below.

In the embodiment shown in FIG. 5 the arm is pivotally connected to thehousing 101. A not shown motor or actuator may be arranged in thehousing 101 or in the arm 102, adapted to move the arm 102 between atleast two positions, one where the lid 120 covers and closes the vessel20; and one where access to the vessel 20 is provided.

In other embodiments, the lid 20 may alternatively or additionally bemanually operable.

In FIG. 5, the arm 102 further comprises not shown rotational drivemeans (motors/actuators) for rotating a sample holder 10 (not shown inFIG. 5, see below), which may be coupled to the arm 102.

FIGS. 2-4 show details of the rinsing device 100 for use in the methodaccording to the invention. For the sake of simplicity, basic componentslike the housing, drive motors/actuators, etc. have been left out.

In FIG. 2, the rinsing device 100 is partially represented by the vessel20 and auxiliary components. The vessel 20 is cup-shaped with an openupwardly facing surface defining an interior cavity. The vessel 20 has abottom 21 and a substantially circular/cylindrical sidewall 22 with anupper edge or rim 23, the substantially circular/cylindrical sidewall 22extending upward from the bottom 21. The vessel 20 is preferablystationary relative to the housing 101 of the apparatus as per FIG. 5.(the housing is not shown in FIGS. 2-4) The vessel 20 is connected or isconnectable to the housing 101 via mounts (not shown) or other suitablemeans.

The vessel 20 may accommodate a sample holder 10 as shown in FIGS. 2 and3.

Details of the sample holder 10 are better explained with reference toFIGS. 1, 6 and 7. The sample holder 10 comprises a circular plate 11formed or provided with a plurality of openings 12 forming receptaclesfor samples 1 (as shown in FIG. 3) each mounted or locked in a base 2.Thus, each opening 12 is adapted for receipt of a sample 1. The sample 1therefore comprises a piece of materialographic material locked in abase 2. The base 2 is preferably cylindrical in shape, and adapted forcooperation with the openings 12 of the sample holder 10.

As shown in FIG. 1 the base 2 may be held in the openings 12 by screwsformed in holes, or internal threads, provided in the rim plate 11. Inother embodiments, the receptacles/openings 12 and/or the bases 2 may beformed with a resilient material to form a tight fit between the two.

As shown in FIG. 6, a resilient retention ring 3 may be formed orarranged on the cylindrical base 2 to secure that the sample cannot passthrough the hole forming the receptacle 12. The samples 1 and the bases2 are loosely placed in the receptacle/hole 12. The resilient retentionring 3 has a tight fit to the materialographic sample 1 and the base 2,and thus provides a larger diameter than the hole 12 thereby preventingthat the sample 1 cannot pass through the hole 12.

FIG. 7 shows an embodiment wherein the samples 2 are retained in thesample holder 10 by means of a retainer plate 200. The retainer plate200 may be made from a flexible or resilient material such as rubber orequivalent. The retainer plate 200 may be configured to rest on an upperface of the sample holder 10. The retainer plate 200 may be providedwith fins 210 configured to urge the underside of the retainer plate 200against the samples 1/bases 2 under centrifugal force. Furthermore, theretention plate 200 may be provided with holes 220 allowing e.g.grinding and/or polishing machines to apply pressure directly onto thesamples 1/bases 2.

Retention of the bases 2/samples 1 in the sample holder 10 may berequired in case the samples are in risk of falling off/exit the sampleholder. This is likely to occur in case relatively light and/or shortbases/samples 1 is mounted in the sample holder 1.

Other ways of arranging the samples 1 in the sample holder 10 mayequally be applied.

The sample holder 10 may further include a stem portion 13 formed at,and extending from, a hub/center 14 of the plate 11 in a directionperpendicular to a plane defined by the plate 11.

In other not shown embodiments, the sample holder 10 may, as analternative to the plate 11, include a plurality of arms extending fromthe hub 14; each arm is including a receptacle 12 for a sample 1 at oneend opposite to the hub 14. A stem portion 13 is again formed at thehub/center 14, and extending from the hub/center 14 in a directionperpendicular to a plane defined by the radiating arms.

At an upper end of the stem portion 13, coupling means 15 are formed,the coupling means 15 being adapted for cooperating with not shownrotational drive means of the rinsing device 100, for example formed inthe arm 102 described in connection with FIG. 5 above, the rotationaldrive means being configured for rotating a sample holder 10 asdescribed below.

In one embodiment, the rotational drive means may be formed in or on alid 120 of the rinsing device 100 or in or on an arm 102 operating theopening and closing of the lid 120. The lid 120 is adapted forcooperation with the upper edge 23 of the vessel 20, such that—in aclosed position—the lid 120 covers and closes the vessel 20 to preventany liquid contained in the vessel 21 from spilling over the upper edge23 even if the liquid is agitated. The lid 120 may be moved between twopositions—one open position, where samples 1 in a sample holder 10 maybe entered into or taken out of the vessel 20 (or attached to the arm102 and the rotational drive means), and one closed position where thelid 120 covers and closes the vessel 20. The lid 102 may be hinged tothe vessel 20 or preferably to the housing 101, as shown in FIG. 5.

In other embodiments (not shown), the lid 120 may be switched betweenits two positions in other manners, e.g. by swinging or translationalmovement. In any embodiment, the lid 102 is preferably automaticallymoveable between its two positions by a not shown drive motor oractuator, and the operation thereof electronically controlled, e.g. byan electronic control unit (not shown) of the rinsing device 100.

In embodiments the rotational drive means (not shown) for rotating thesample holder 10 are located in an arm 102 extending from the housing101, or from the edge 23 of the vessel 20, the lid 120 and the arm 102being configured such that in combination they may cover and close thevessel 20 in the closed position of the lid 120.

The coupling means 15, at the upper end of the stem portion 13 of thesample holder 10, are preferably formed such that they may alsocooperate with a grinding device (not shown) for grinding a plurality ofsamples 1 arranged in a sample holder 10. Thus, the sample holder 10with the one or more materialographic samples may be easily transferredfrom the grinding device to the rinsing device and vice versa. In otherembodiments (not shown), an adapter may secure that a sample holder 10configured for either a rinsing device or a grinding device, may betransferred to the other of the two.

When the lid 120 is in its open position, a sample holder 10 may beconnected to the rotational drive means. The rotational drive means areconfigured for rotating the sample holder 10 when the lid is closed, andin some embodiments also when the lid is closing, see below. Therotational drive means are preferably connected to and controlled by theelectronic control device (not shown) of the rinsing device 100.

The rinsing device 100 further comprises a source of ultrasonic waves,i.e. ultrasound, such as an ultrasound transducer 25. The source ofultrasound is preferably arranged in the housing 101 of the rinsingdevice. In other embodiments, the source of ultrasound may be located inor on the vessel 20 or in or on the lid 120 or in or on the arm 102.Preferably, and as shown in FIGS. 2-4, the ultrasound source/transducer25 is formed in the bottom 21 of the vessel 20. As shown, there can beseveral sources 25. In other embodiments, there may be just a singleultrasound source/transducer 25, and in yet others there may be 3, 4 or5. Preferably, as shown in FIGS. 2-4, the ultrasound sources/transducers25 may be placed in different positions, asymmetrically relative to theaxis A.

The source of ultrasonic waves 25 is arranged in the rinsing device 100such that one or more materialographic samples 1 in a sample holder 10placed in the vessel 20 may be subjected to ultrasound. The source ofultrasound 25 is preferably connected to and controlled by theelectronic control device of the rinsing device 100.

The rinsing device 100 further comprises means for filling and emptyingthe vessel 20 with a rinsing liquid.

In a preferred embodiment, the rinsing liquid is pure water, i.e. waterwith no additives.

The rinsing device 100 may preferably be equipped with means forconnecting to a source of rinsing liquid, such as a water tap, or arinsing liquid container being arranged in the rinsing device 100. Therinsing device 100 may further comprise pumping means (not shown)configured for pumping rinsing liquid into and/or out of the vessel 20.In other embodiments the rinsing device may be connectable to a sourceof pressurized rinsing liquid with the purpose of supplying the vessel.In either case a pump 105 may be provided for emptying the vessel 20. Inany embodiment, any valves and/or pump or pumps are preferably connectedto and controlled by the electronic control device of the rinsing device100.

Preferably, at least one inlet 26 for rinsing liquid is provided throughthe bottom of the vessel 20. The inlet 26 is connected/connectable to asource of rinsing liquid as described above through a suitable piping, arinsing liquid supply pipe 30. Preferably, the inlet 26 is provided witha deflector/water damper/flow damper 27 for deflecting the stream/jet ofrinsing liquid away from a direction to parallel to the rotational axis,A, of the sample holder 10, when inserted in the vessel 20, i.e. awayfrom a vertical axis. The deflector 27 is arranged to form a “roof” overthe inlet opening. Thereby, it may be achieved that the filling of thevessel 20 with rinsing liquid may be commenced before the lid closescompletely to close-of the upper open surface of the vessel 20. This maybe achieved, while still providing the inlet 26 through the bottom 21 ofthe vessel 20, which allows for a very compact rinsing device 21.

Preferably, an outlet 28 for used rinsing liquid is also providedthrough the bottom 21 of the vessel 20. The outlet 28 isconnected/connectable to a drain through a suitable piping, a liquidexit pipe 31, see FIG. 4, through the rinsing device 100. Thereby, thevessel 20 may be evacuated from rinsing liquid under the influence ofgravity alone. However, in other embodiments, the liquid exit pipe maybe connected/connectable to a vacuum source/vacuum pump 105, such asshown in FIGS. 3 and 4. Such a pump 105 is preferably connected to andcontrolled by the electronic control device of the rinsing device 100.

In a preferred embodiment, the inlet 26 and outlet 28, and as shown inFIGS. 2-4, is one and the same. Thereby space may be saved, and a morecompact rinsing device 100 may be achieved. A valve may control thecommon inlet/outlet 26, 28 function. So that inlet rinsing liquid doesnot end in the outlet pipe 31.

In further embodiments, the rinsing device 100 may further be equippedwith means for supplying alcohol or methylated spirit into the vessel 20or more particularly spraying alcohol or methylated spirit on thematerialographic samples 1 in the sample holder 10. The rinsing device100 may preferably be equipped with means, such as an alcohol supplytube 32, for connecting to a source of alcohol or methylated spirit,such as a container being arranged in the rinsing device 100 or inconnection with the rinsing device 100. The rinsing device 100 mayfurther comprise pumping means (not shown) configured for pumpingalcohol or methylated spirit into the vessel 20 from the container. Inother embodiments the rinsing device may be connectable to a source ofpressurized alcohol or methylated spirit. From the alcohol supply tube32, alcohol or methylated spirit is injected into the vessel, e.g. via anozzle 33 that may be formed in the sidewall 22 of the vessel 20. Inother not shown embodiments, the nozzle 33 may be formed in the lid orin the bottom 21 of the vessel 20.

The rinsing device 100 may further be equipped with or connectable tovacuum producing means, such as a pump, for sucking out the alcohol ormethylated spirit fumes from the vessel 20 via a fume outlet 29 andsuitable piping. In any embodiment, any valves and/or pump or pumps arepreferably connected to and controlled by the electronic control deviceof the rinsing device 100.

In one embodiment, not shown, the one or more outlets 28 for rinsingliquid and the one or more fume outlets 29 for alcohol or methylatedspirit fumes may be the same outlet formed through the bottom 21 of thevessel 20. In this case, the outlet(s) 28, 29 is/are connected to anexit pipe 31, and the exit pipe 31 branches of in two, an upper branch31 a, through which the alcohol or methylated spirit fumes can beextracted from the rinsing apparatus 100, and a lower branch 31 b,configured to evacuate the rinsing liquid from the vessel 100. The lowerbranch 31 b may be connectable to a sewage pipe. A vacuum pump or othersource of vacuum may be connected to the upper branch. As describedabove, the vacuum pump is preferably connected to and controlled by theelectronic control device of the rinsing device 100.

In another embodiment, there is provided one outlet 28 for the rinsingliquid, in the bottom 21 of the vessel 20, and one fume outlet 29 forthe alcohol or methylated spirit fumes, preferably but not necessarilyformed through the sidewall 22 of the vessel 20. In the embodiment shownin FIGS. 2-4 the fume outlet 29 is formed through the sidewall 22 of thevessel 20. In this case the fume outlet 29 for the alcohol or methylatedspirit fumes may be connected to an upper fume exit pipe 34, and theoutlet 28 for the rinsing liquid to a lower rinsing liquid exit pipe 31,as shown in FIGS. 3 and 4. At least the upper fume exit pipe 34 may beconnectable to a source of suction/vacuum, such as a pump/vacuum pump,which may be connected to and controlled by the electronic controldevice of the rinsing device 100. A pipe connection 35 may be providedbetween the upper fume exit pipe 34, and a drain pipe 40 forming anextension of the lower rinsing liquid exit pipe 31. Thus the upper fumeexit pipe 34 and the outlet 29 for the alcohol or methylated spiritfumes may function as an overspill for the vessel 20, any rinsingliquid/water entering the upper fume exit pipe 34 being drained of tothe lower rinsing liquid exit pipe 31 via the pipe connection 35.

In FIG. 3 the liquid exit pipe 31 is not shown. In FIG. 4 it is shownhow the inlet/outlet 26/28 of FIGS. 3 and 4 may be connected to a drainby the liquid exit pipe 31. In FIG. 4 it is seen how the liquid exitpipe 31 connects to pump 105, so that the vessel may be quicklyevacuated. The pump 105 is connected to a drain pipe 40 via pipe 39forming a water lock.

In addition to any of the above mentioned embodiments the rinsing devicemay further be equipped with means for supplying compressed air to theinside of the vessel 20, for the purpose of drying the samples 1 in thesample holder when water has been drained from the vessel 20. Thecompressed air may be supplied from a ventilation unit (not shown) andthe air led from ambient to the vessel through suitable piping (notshown). The piping for compressed air may be led through the vessels 20side wall 22, through the lid, or through the bottom 21 of the vessel20. In further embodiments the compressed air may further be heated bysuitable heating means (not shown) in the compressed air piping or inthe ventilation unit. The ventilation unit and/or the heating meansis/are preferably connected to and controlled by the electronic controldevice of the rinsing device 100.

In addition to any of the above mentioned embodiments the rinsing devicemay further be equipped with not shown means for supplying oil to thesamples 1 in the vessel 20. The oil is preferably delivered through anozzle, connected via a suitable piping to a pressurized source of oilor source of oil connected via pump. Thereby, a mist of lubricating oilmay be sprayed on the samples 1, which may be advantageous especially inthe case, the materialographic samples 1 are cast iron samples. Thelubrication oil will prevent or decrease oxidation. The oil nozzleand/or the oil pump are preferably connected to and controlled by theelectronic control device of the rinsing device 100.

By the above mentioned embodiments of the rinsing device, it may beachieved that the rinsing device 100 may be a semi-automated stand-aloneunit, where materialographic samples 1 arranged in a sample holder maybe manually transferred from a grinding device to a rinsing device 100by an operator, and once the rinsing process is initiated everything maybe automatically controlled by the electronic control device of therinsing device 100. The electronic control device of the rinsing device100 may be configured for running various rinsing programs, which may bechosen by the operator prior to the process, and depending e.g. on thetype of materialographic sample 1. When the sample 1 or samples 1 in therinsing device 100 are dry, the sample holder 10 with the samples 1 maybe removed for further grinding or for examination and furtherinvestigation.

However, in other aspects of the invention, the embodiments of therinsing device 100, described above may be integrated with a grindingdevice, with e.g. a robot arm transferring the sample holder 10 betweenthe grinding device and the rinsing device, the robot arm having meansfor cooperating with the coupling means 15 on the stem 13 of the sampleholder 10.

In the following various embodiments of the method according to theinvention will be described, with reference to the figures, and to theembodiments of the rinsing device as described above.

One method of rinsing materialographic samples 1 according to theinvention involves initially arranging one or more materialographicsamples 1 in a sample holder 10; the samples either comes from agrinding device, where they have been ground and therefore needs to berinsed, or they need to be rinsed before the first grinding. Thesampling holder 10 with one or more samples 1 is then coupled/connectedto a rotation head of the rinsing device 100 as described in connectionwith any of the embodiments above. This may be an automatic transfer,e.g. by a robotic arm as indicated above, or it may be done manually byan operator. In the latter case, the operator may then start the rinsingprocess e.g. by pressing a button, for example after choosing apre-coded rinsing program stored in the electronic control unit of therinsing device 100. Then the sample holder 10, which is now coupled tothe rotation head, is entered into the vessel 20 by an actuatorcontrolled by the electronic control unit of the rinsing device 100.Then the lid 120 is closed or starts closing. During or after closing ofthe lid, a number of steps are initiated: the vessel 20 starts fillingup with a rinsing liquid; the rotation head starts spinning/rotating thesample holder 10 relative to the vessel 20; and the materialographicsamples 1 in the sample holder 10 are subjected to ultrasonic waves,i.e. they are subjected to influence of ultrasound.

In one embodiment of the method the step of subjecting thematerialographic samples 1 in the sample holder 10 to ultrasonic wavesis initiated at the same time as the rinsing liquid begins to fill thevessel 20. In another embodiment, the step of subjecting thematerialographic samples 1 in the sample holder 10 to ultrasonic wavesis initiated before the rinsing liquid begins to fill the vessel 20.However, in a preferred embodiment, the step of subjecting thematerialographic samples 1 in the sample holder 10 to ultrasonic wavesis initiated during the filling of the vessel 20 with rinsing liquid.Preferably, the ultrasound is initiated within 0.5-2 seconds, such as 1second after the filling of the vessel starts, but before the vessel 20has been filled. Thus the ultrasound is turned on while the vessel 20fills up. It has been found that thereby eventual dirt in the vessel 20is loosened.

Further, the rotation of the sample holder 10, by the rotation head isinitiated after the ultrasonic waves are initiated. Preferably, therotation is initiated within 0.5-2 seconds, such as 1 second after theultrasound influence has begun.

In any of the above embodiments the method may comprise the step ofinjecting said rinsing liquid through a bottom 21 of said vessel 20,where the path of said injected rinsing liquid is deflected from adirection parallel to the axis of rotation of the sample holder 10, andwhere the injection of rinsing liquid is initiated before a step ofclosing set said lid is completed.

The closing of the lid commences at the very beginning of the rinsingprocedure. As each operation takes time, filling of the vessel 20 5-10seconds, and closing of the lid 3-6 seconds, time can be saved bycommencing the injection of rinsing liquid before the lid is completelyclosed. The rinsing liquid is preferably injected at a pressure of 2-5bar, preferably 3 bar.

The rotations of the sample holder 10 are preferably controlled in thisphase to 50-200 revolutions per minute (rpm), more preferably 50-70 rpm.This rotation in combination with the ultrasound in combination withsubmerging the samples into a rinsing liquid has proven very efficientin rinsing materialographic samples. In fact the method has proven soefficient that the rinsing liquid may be pure water, without anyadditives, such as detergents or other chemicals. Therefore, a veryclean and environmentally friendly rinsing process is achieved.

In a preferred embodiment therefore the rinsing liquid is pure water. Inthe context of the present application, by pure water is meant tap waterwithout any additives, such as detergents, alcohol, or organic solvents,e.g. acetone, or weak acids or basic solutions. Ultra clean water,desalinated water, or demineralized water is not necessary.

Rotation of the sample holder will result in acceleration of the rinsingliquid until it generates a vortex (vortical flow). The larger thediameter of the sample holder is—compared to the diameter of thevessel—the faster this state is established. During vortical flow, thespeed of the rinsing liquid relative to the sample holder becomes verysmall, and therefore affects the rinsing action negatively. In order tobreak the vortical flow, the rotational direction may be alternated.E.g. a pattern, where the rotation is 5 seconds in one direction (e.g.clockwise), followed by 5 seconds in the opposite direction has beenfound useful. Further, alternations with a sequence of 21/2 secondintervals or 2 or 1 second has also proven efficient.

Vortical flow may also be avoided or diminished by having anasymmetrical placement of the sample holder inside the vessel, or by theuse of baffles on the inside of the vessel. Each of these features maybe used in addition or as alternatives to the above mentioned reversalof the rotational direction.

During application of ultrasound, the flow of the water and rotationshould be kept at a rotational speed where turbulence in the liquid isminimized as this will decrease the efficiency of the ultrasound.

The ultrasound may be applied in 15-30 seconds, preferably in 18-27seconds, such as 20-25 seconds.

The rotation is preferably applied in the above mentioned speed (andpossibly in alternating direction) in 18-35 seconds, such as 20-30seconds.

The method may further comprise the step of emptying the rinsing liquidfrom the vessel 20 while still rotating the sample holder 10 in thevessel 20. The rinsing liquid is drained from the vessel e.g. by openinga valve in connection with the outlet 28 whereby the outlet being formedin the bottom 21 of the vessel 20 will drain under the influence ofgravity. However, in order to speed up the process, suction is appliedto evacuate the vessel 20 from water.

Preferably, the ultrasound is maintained for a period after emptying therinsing liquid is initiated. Preferably in 1-3 seconds, such as 2seconds.

The rotational speed of the sample holder 10 is increased after theemptying of the rinsing liquid is initiated. The speed increase iscommenced 2-10 seconds, such as 3-8, such as 4-7, such as 5-6 secondsthe emptying of the rinsing liquid is initiated. The rotational speed isincreased to 1000-3000 rpm, such as 1500-2500 rpm, such as 2000 rpm.

This speeding up of the rotation dries the samples 1 and the sampleholder 10. The high speed spinning is maintained from 10 to 30 seconds,such as 15-25 seconds.

After the high speed spinning, the sample holder stops and the lid mayopen. Thereby the sample holder 10 with the samples 1 may be removed andplaced in the grinding device or they may be removed for examination.Again this may be done automatically or manually.

In an embodiment the method further comprises the step of sprayingalcohol or methylated spirit on the materialographic samples 1 in thesample holder 10 after emptying the rinsing liquid from the vessel 20.

Preferably, the step of spraying alcohol or methylated spirit on thematerialographic samples 1 in the sample holder 10 is performed whilerotating the sample holder 10 in the vessel 20, at the above mentionedhigh rotational speed, and consequently after the ultrasound isdiscontinued.

The spraying with alcohol or methylated spirit during the high speedrotation, helps displacing the rinsing liquid/pure water, and improvesthe surface tension on the samples 1 and thereby loosens any residualdirt.

The spraying with alcohol or methylated spirit may be applied for 2-8seconds during the high speed rotation, such as 3-7 seconds, such as 4-6seconds, such as 5 seconds.

In an embodiment the method further comprises the step of applyingcompressed air to the materialographic samples 1 in the sample holder 10after emptying the rinsing liquid from the vessel 20.

Preferably, the step of applying compressed air to the materialographicsamples 1 in the sample holder 10 is performed while rotating the sampleholder 10 in the vessel 20, at the above mentioned high rotationalspeed, and consequently after the ultrasound is discontinued.

In a further embodiment the method further comprises the step ofapplying compressed air to the materialographic samples 1 in the sampleholder 10 after the spraying alcohol or methylated spirit has ended.

The application of compressed air may be applied for 5-15 seconds duringthe high speed rotation, such as 10-14 seconds, such as 11-13 seconds,such as 12 seconds.

The compressed air is preferably applied at a pressure of 4-8 bar, suchas 5-7 bar, such as 6 bar.

In further embodiments, the step of applying compressed aid may becontinued in a short period of a few seconds after the rotation stops,such s 1-4 seconds, such as 2 seconds.

In an embodiment the method further comprises the step of sprayinglubricating oil on the materialographic samples 1 in the sample holder10 after emptying the rinsing liquid from the vessel 20. Preferably, thestep of spraying lubricating oil on the materialographic samples 1 inthe sample holder 10 is performed while rotating the sample holder 10 inthe vessel 20, at the above mentioned high rotational speed, andconsequently after the ultrasound is discontinued.

The above mentioned steps are preferably controlled by the electroniccontrol unit of the rinsing device.

In relation to all of the above embodiments the ultrasound applied bythe ultrasound sources/transducers 25 are preferably in the range of30-150 kHz. Preferably, the ultrasound sources/transducers 25 emitultrasound at 35 kHz. Ultrasound up to the order of 145 kHz may be usedfor smaller particles.

The method according to any of the above mentioned embodiments may beimplemented in a device according to the embodiments of the rinsingdevice described further above.

The teaching of this invention has numerous advantages. Differentembodiments or implementations may yield one or more of the followingadvantages. It should be noted that this is not an exhaustive list andthere may be other advantages which are not described herein. Oneadvantage of the teaching of this method is that it provides a greatflexibility in designing and operating a rinsing or rinsing and grindingsystem.

Although the teaching of this application has been described in detailfor purpose of illustration, it is understood that such detail is solelyfor that purpose, and variations can be made therein by those skilled inthe art without departing from the scope of the teaching of thisapplication.

The terms “comprising” and/or “including” as used in the claims does notexclude other elements or steps. The term “a” or “an” as used in theclaims does not exclude a plurality.

1. A rinsing apparatus configured to rinse materialographic samples,comprising: a sample holder configured to receive materialographicsamples, wherein the materialographic samples comprise at least one ofmetal, polymer or ceramic samples that have been cut and subjected to atleast one of a grinding or lapping procedure; a rotation head configuredto rotate the sample holder; a vessel configured to receive the sampleholder and a rinsing liquid, means for filling and emptying the vesselwith rinsing liquid; means for applying ultrasound to the rinsingliquid; control means configured to control at least one of: filling ofthe vessel with a rinsing liquid by injecting rinsing liquid through aninlet provided in the vessel to submerge the materialographic samples inthe rinsing liquid, subjecting the rinsing liquid and thematerialographic samples to ultrasound, or rotating the sample holderincluding the materialographic samples relative to the vessel.
 2. Therinsing apparatus according to claim 1, wherein the rinsing apparatusfurther comprises means to maintain the materialographic samples in thesample holder during rotation of the sample holder.
 3. The rinsingapparatus according to claim 2, wherein the means to maintain thematerialographic samples in the sample holder comprises one or moreclamps configured to clamp the materialographic samples to the sampleholder.
 4. The rinsing apparatus according to claim 1, furthercomprising: a retainer plate configured to be arranged on top of thesample holder to maintain the materialographic samples in the sampleholder during rotation of the sample holder.
 5. The rinsing apparatusaccording to claim 4, wherein the retainer plate is made from a flexiblematerial.
 6. The rinsing apparatus according to claim 4, wherein theretainer plate is, on an upper face, provided with fins configured tourge the retainer plate against the sample holder during rotation of thesample holder.
 7. The rinsing apparatus according to claim 4, whereinthe retainer plate is, on a face facing the sample holder, provided withmeans to interlock the retainer plate with respect to the sample holder.8. The rinsing apparatus according to claim 1, wherein the inlet islocated at the bottom of the vessel.